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<h1><span class="logo-braces">{ }</span> <a href="http://codemirror.net/">CodeMirror</a></h1>

<pre class="grey">
<img src="css/baboon.png" class="logo" alt="logo"/>/* User manual and
   reference guide */
</pre>

<div class="clear">
<div class="leftbig blk">

<h2 id="overview">Overview</h2>

<p>CodeMirror is a code-editor component that can be embedded in
  Web pages. It provides <em>only</em> the editor component, no
  accompanying buttons
  (see <a href="http://www.octolabs.com/javascripts/codemirror-ui/">CodeMirror
    UI</a> for a drop-in button bar), auto-completion, or other IDE
  functionality. It does provide a rich API on top of which such
  functionality can be straightforwardly implemented.</p>

<p>CodeMirror works with language-specific modes. Modes are
  JavaScript programs that help color (and optionally indent) text
  written in a given language. The distribution comes with a few
  modes (see the <code>mode/</code> directory), and it isn't hard
  to <a href="#modeapi">write new ones</a> for other languages.</p>

<h2 id="usage">Basic Usage</h2>

<p>The easiest way to use CodeMirror is to simply load the script
  and style sheet found under <code>lib/</code> in the distribution,
  plus a mode script from one of the <code>mode/</code> directories
  and a theme stylesheet from <code>theme/</code>. (See
  also <a href="compress.html">the compression helper</a>.) For
  example:</p>

    <pre>&lt;script src="lib/codemirror.js">&lt;/script>
&lt;link rel="stylesheet" href="lib/codemirror.css">
&lt;script src="mode/javascript/javascript.js">&lt;/script>
&lt;link rel="stylesheet" href="theme/default.css"></pre>

<p>(If you use a theme other than <code>default.css</code>, you
  also have to specify the
  <a href="#option_theme"><code>theme</code></a> option.) Having
  done this, an editor instance can be created like this:</p>

<pre>var myCodeMirror = CodeMirror(document.body);</pre>

<p>The editor will be appended to the document body, will start
  empty, and will use the mode that we loaded. To have more control
  over the new editor, a configuration object can be passed
  to <code>CodeMirror</code> as a second argument:</p>

    <pre>var myCodeMirror = CodeMirror(document.body, {
  value: "function myScript(){return 100;}\n",
  mode:  "javascript"
});</pre>

<p>This will initialize the editor with a piece of code already in
  it, and explicitly tell it to use the JavaScript mode (which is
  useful when multiple modes are loaded).
  See <a href="#config">below</a> for a full discussion of the
  configuration options that CodeMirror accepts.</p>

<p>In cases where you don't want to append the editor to an
  element, and need more control over the way it is inserted, the
  first argument to the <code>CodeMirror</code> function can also
  be a function that, when given a DOM element, inserts it into the
  document somewhere. This could be used to, for example, replace a
  textarea with a real editor:</p>

    <pre>var myCodeMirror = CodeMirror(function(elt) {
  myTextArea.parentNode.replaceChild(elt, myTextArea);
}, {value: myTextArea.value});</pre>

<p>However, for this use case, which is a common way to use
  CodeMirror, the library provides a much more powerful
  shortcut:</p>

<pre>var myCodeMirror = CodeMirror.fromTextArea(myTextArea);</pre>

<p>This will, among other things, ensure that the textarea's value
  is updated when the form (if it is part of a form) is submitted.
  See the <a href="#fromTextArea">API reference</a> for a full
  description of this method.</p>

<h2 id="config">Configuration</h2>

<p>Both the <code>CodeMirror</code> function and
  its <code>fromTextArea</code> method take as second (optional)
  argument an object containing configuration options. Any option
  not supplied like this will be taken
  from <code>CodeMirror.defaults</code>, an object containing the
  default options. You can update this object to change the defaults
  on your page.</p>

<p>Options are not checked in any way, so setting bogus option
  values is bound to lead to odd errors.</p>

<p><em>Note:</em> CodeMirror
  2 <a href="internals.html#summary">does not support</a>
  line-wrapping. I would have very much liked to support it, but it
  combines extremely poorly with the way the editor is
  implemented.</p>

<p>These are the supported options:</p>

<dl>
  <dt id="option_value"><code>value (string)</code></dt>
  <dd>The starting value of the editor.</dd>

  <dt id="option_mode"><code>mode (string or object)</code></dt>
  <dd>The mode to use. When not given, this will default to the
    first mode that was loaded. It may be a string, which either
    simply names the mode or is
    a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type
    associated with the mode. Alternatively, it may be an object
    containing configuration options for the mode, with
    a <code>name</code> property that names the mode (for
    example <code>{name: "javascript", json: true}</code>). The demo
    pages for each mode contain information about what configuration
    parameters the mode supports. You can ask CodeMirror which modes
    and MIME types are loaded with
    the <code>CodeMirror.listModes</code>
    and <code>CodeMirror.listMIMEs</code> functions.
  </dd>

  <dt id="option_theme"><code>theme (string)</code></dt>
  <dd>The theme to style the editor with. You must make sure the
    CSS file defining the corresponding <code>.cm-s-[name]</code>
    styles is loaded (see
    the <a href="theme/"><code>theme</code></a> directory in the
    distribution).
  </dd>

  <dt id="option_indentUnit"><code>indentUnit (integer)</code></dt>
  <dd>How many spaces a block (whatever that means in the edited
    language) should be indented. The default is 2.
  </dd>

  <dt id="option_indentWithTabs"><code>indentWithTabs (boolean)</code></dt>
  <dd>Whether, when indenting, the first N*8 spaces should be
    replaced by N tabs. Default is false.
  </dd>

  <dt id="option_tabMode"><code>tabMode (string)</code></dt>
  <dd>Determines what happens when the user presses the tab key.
    Must be one of the following:
    <dl>
      <dt><code>"classic" (the default)</code></dt>
      <dd>When nothing is selected, insert a tab. Otherwise,
        behave like the <code>"shift"</code> mode. (When shift is
        held, this behaves like the <code>"indent"</code> mode.)
      </dd>
      <dt><code>"shift"</code></dt>
      <dd>Indent all selected lines by
        one <a href="#option_indentUnit"><code>indentUnit</code></a>.
        If shift was held while pressing tab, un-indent all selected
        lines one unit.
      </dd>
      <dt><code>"indent"</code></dt>
      <dd>Indent the line the 'correctly', based on its syntactic
        context. Only works if the
        mode <a href="#indent">supports</a> it.
      </dd>
      <dt><code>"default"</code></dt>
      <dd>Do not capture tab presses, let the browser apply its
        default behaviour (which usually means it skips to the next
        control).
      </dd>
    </dl>
  </dd>

  <dt id="option_enterMode"><code>enterMode (string)</code></dt>
  <dd>Determines whether and how new lines are indented when the
    enter key is pressed. The following modes are supported:
    <dl>
      <dt><code>"indent" (the default)</code></dt>
      <dd>Use the mode's indentation rules to give the new line
        the correct indentation.
      </dd>
      <dt><code>"keep"</code></dt>
      <dd>Indent the line the same as the previous line.</dd>
      <dt><code>"flat"</code></dt>
      <dd>Do not indent the new line.</dd>
    </dl>
  </dd>

  <dt id="option_electricChars"><code>electricChars (boolean)</code></dt>
  <dd>Configures whether the editor should re-indent the current
    line when a character is typed that might change its proper
    indentation (only works if the mode supports indentation).
    Default is true.
  </dd>

  <dt id="option_smartHome"><code>smartHome (boolean)</code></dt>
  <dd>Configures whether the home key takes you to the first
    non-whitespace character (unless already there) or to the start
    of the line. On by default.
  </dd>

  <dt id="option_lineNumbers"><code>lineNumbers (boolean)</code></dt>
  <dd>Whether to show line numbers to the left of the editor.</dd>

  <dt id="option_firstLineNumber"><code>firstLineNumber (integer)</code></dt>
  <dd>At which number to start counting lines. Default is 1.</dd>

  <dt id="option_gutter"><code>gutter (boolean)</code></dt>
  <dd>Can be used to force a 'gutter' (empty space on the left of
    the editor) to be shown even when no line numbers are active.
    This is useful for setting <a href="#setMarker">markers</a>.
  </dd>

  <dt id="option_fixedGutter"><code>fixedGutter (boolean)</code></dt>
  <dd>When enabled (off by default), this will make the gutter
    stay visible when the document is scrolled horizontally.
  </dd>

  <dt id="option_readOnly"><code>readOnly (boolean)</code></dt>
  <dd>This disables editing of the editor content by the user.
    (Changes through API functions will still be possible.) If you
    also want to disable the cursor, use <code>"nocursor"</code> as
    a value for this option, instead of <code>true</code>.
  </dd>

  <dt id="option_onChange"><code>onChange (function)</code></dt>
  <dd>When given, this function will be called every time the
    content of the editor is changed. It will be given the editor
    instance as only argument.
  </dd>

  <dt id="option_onCursorActivity"><code>onCursorActivity (function)</code></dt>
  <dd>Like <code>onChange</code>, but will also be called when the
    cursor moves without any changes being made.
  </dd>

  <dt id="option_onGutterClick"><code>onGutterClick (function)</code></dt>
  <dd>When given, will be called whenever the editor gutter (the
    line-number area) is clicked. Will be given the editor instance
    as first argument, the (zero-based) number of the line that was
    clicked as second argument, and the raw <code>mousedown</code>
    event object as third argument.
  </dd>

  <dt id="option_onFocus"><code>onFocus, onBlur (function)</code></dt>
  <dd>The given functions will be called whenever the editor is
    focused or unfocused.
  </dd>

  <dt id="option_onScroll"><code>onScroll (function)</code></dt>
  <dd>When given, will be called whenever the editor is
    scrolled.
  </dd>

  <dt id="option_onHighlightComplete"><code>onHighlightComplete (function)</code></dt>
  <dd>Whenever the editor's content has been fully highlighted,
    this function (if given) will be called. It'll be given a single
    argument, the editor instance.
  </dd>

  <dt id="option_matchBrackets"><code>matchBrackets (boolean)</code></dt>
  <dd>Determines whether brackets are matched whenever the cursor
    is moved next to a bracket.
  </dd>

  <dt id="option_workTime"><code>workTime, workDelay (number)</code></dt>
  <dd>Highlighting is done by a pseudo background-thread that will
    work for <code>workTime</code> milliseconds, and then use
    timeout to sleep for <code>workDelay</code> milliseconds. The
    defaults are 200 and 300, you can change these options to make
    the highlighting more or less aggressive.
  </dd>

  <dt id="option_undoDepth"><code>undoDepth (integer)</code></dt>
  <dd>The maximum number of undo levels that the editor stores.
    Defaults to 40.
  </dd>

  <dt id="option_tabindex"><code>tabindex (integer)</code></dt>
  <dd>The <a href="http://www.w3.org/TR/html401/interact/forms.html#adef-tabindex">tab
    index</a> to assign to the editor. If not given, no tab index
    will be assigned.
  </dd>

  <dt id="option_document"><code>document (DOM document)</code></dt>
  <dd>Use this if you want to display the editor in another DOM.
    By default it will use the global <code>document</code>
    object.
  </dd>

  <dt id="option_onKeyEvent"><code>onKeyEvent (function)</code></dt>
  <dd>This provides a rather low-level hook into CodeMirror's key
    handling. If provided, this function will be called on
    every <code>keydown</code>, <code>keyup</code>,
    and <code>keypress</code> event that CodeMirror captures. It
    will be passed two arguments, the editor instance and the key
    event. This key event is pretty much the raw key event, except
    that a <code>stop()</code> method is always added to it. You
    could feed it to, for example, <code>jQuery.Event</code> to
    further normalize it.<br>This function can inspect the key
    event, and handle it if it wants to. It may return true to tell
    CodeMirror to ignore the event. Be wary that, on some browsers,
    stopping a <code>keydown</code> does not stop
    the <code>keypress</code> from firing, whereas on others it
    does. If you respond to an event, you should probably inspect
    its <code>type</code> property and only do something when it
    is <code>keydown</code> (or <code>keypress</code> for actions
    that need character data).
  </dd>
</dl>

<h2 id="styling">Customized Styling</h2>

<p>Up to a certain extent, CodeMirror's look can be changed by
  modifying style sheet files. The style sheets supplied by modes
  simply provide the colors for that mode, and can be adapted in a
  very straightforward way. To style the editor itself, it is
  possible to alter or override the styles defined
  in <a href="lib/codemirror.css"><code>codemirror.css</code></a>.</p>

<p>Some care must be taken there, since a lot of the rules in this
  file are necessary to have CodeMirror function properly. Adjusting
  colors should be safe, of course, and with some care a lot of
  other things can be changed as well. The CSS classes defined in
  this file serve the following roles:</p>

<dl>
  <dt id="class_CodeMirror"><code>CodeMirror</code></dt>
  <dd>The outer element of the editor. This should be used for
    borders and positioning. Can also be used to set styles that
    should hold for everything inside the editor (such as font
    and font size), or to set a background.
  </dd>

  <dt id="class_CodeMirror_scroll"><code>CodeMirror-scroll</code></dt>
  <dd>This determines whether the editor scrolls (<code>overflow:
    auto</code> + fixed height). By default, it does. Giving
    this <code>height: auto; overflow: visible;</code> will cause
    the editor to resize to fit its content.
  </dd>

  <dt id="class_CodeMirror_focused"><code>CodeMirror-focused</code></dt>
  <dd>Whenever the editor is focused, the top element gets this
    class. This is used to hide the cursor and give the selection a
    different color when the editor is not focused.
  </dd>

  <dt id="class_CodeMirror_gutter"><code>CodeMirror-gutter</code></dt>
  <dd>Use this for giving a background or a border to the editor
    gutter. Don't set any padding here,
    use <code>CodeMirror-gutter-text</code> for that. By default,
    the gutter is 'fluid', meaning it will adjust its width to the
    maximum line number or line marker width. You can also set a
    fixed width if you want.
  </dd>

  <dt id="class_CodeMirror_gutter_text"><code>CodeMirror-gutter-text</code></dt>
  <dd>Used to style the actual line numbers. For the numbers to
    line up, you must make sure that the font in the gutter is the
    same as the one in the rest of the editor, so you should
    probably only set font style and size in
    the <code>CodeMirror</code> class.
  </dd>

  <dt id="class_CodeMirror_lines"><code>CodeMirror-lines</code></dt>
  <dd>The visible lines. If this has vertical
    padding, <code>CodeMirror-gutter</code> should have the same
    padding.
  </dd>

  <dt id="class_CodeMirror_cursor"><code>CodeMirror-cursor</code></dt>
  <dd>The cursor is a block element that is absolutely positioned.
    You can make it look whichever way you want.
  </dd>

  <dt id="class_CodeMirror_selected"><code>CodeMirror-selected</code></dt>
  <dd>The selection is represented by <code>span</code> elements
    with this class.
  </dd>

  <dt id="class_CodeMirror_matchingbracket"><code>CodeMirror-matchingbracket</code>,
    <code>CodeMirror-nonmatchingbracket</code></dt>
  <dd>These are used to style matched (or unmatched) brackets.</dd>
</dl>

<p>The actual lines, as well as the cursor, are represented
  by <code>pre</code> elements. By default no text styling (such as
  bold) that might change line height is applied. If you do want
  such effects, you'll have to give <code>CodeMirror pre</code> a
  fixed height. Also, you must still take care that character width
  is constant.</p>

<p>If your page's style sheets do funky things to
  all <code>div</code> or <code>pre</code> elements (you probably
  shouldn't do that), you'll have to define rules to cancel these
  effects out again for elements under the <code>CodeMirror</code>
  class.</p>

<h2 id="api">Programming API</h2>

<p>A lot of CodeMirror features are only available through its API.
  This has the disadvantage that you need to do work to enable them,
  and the advantage that CodeMirror will fit seamlessly into your
  application.</p>

<p>Whenever points in the document are represented, the API uses
  objects with <code>line</code> and <code>ch</code> properties.
  Both are zero-based. CodeMirror makes sure to 'clip' any positions
  passed by client code so that they fit inside the document, so you
  shouldn't worry too much about sanitizing your coordinates. If you
  give <code>ch</code> a value of <code>null</code>, or don't
  specify it, it will be replaced with the length of the specified
  line.</p>

<dl>
  <dt id="getValue"><code>getValue() → string</code></dt>
  <dd>Get the current editor content.</dd>
  <dt id="setValue"><code>setValue(string)</code></dt>
  <dd>Set the editor content.</dd>

  <dt id="getSelection"><code>getSelection() → string</code></dt>
  <dd>Get the currently selected code.</dd>
  <dt id="replaceSelection"><code>replaceSelection(string)</code></dt>
  <dd>Replace the selection with the given string.</dd>

  <dt id="focus"><code>focus()</code></dt>
  <dd>Give the editor focus.</dd>

  <dt id="setOption"><code>setOption(option, value)</code></dt>
  <dd>Change the configuration of the editor. <code>option</code>
    should the name of an <a href="#config">option</a>,
    and <code>value</code> should be a valid value for that
    option.
  </dd>
  <dt id="getOption"><code>getOption(option) → value</code></dt>
  <dd>Retrieves the current value of the given option for this
    editor instance.
  </dd>

  <dt id="cursorCoords"><code>cursorCoords(start) → object</code></dt>
  <dd>Returns an <code>{x, y, yBot}</code> object containing the
    coordinates of the cursor relative to the top-left corner of the
    page. <code>yBot</code> is the coordinate of the bottom of the
    cursor. <code>start</code> is a boolean indicating whether you
    want the start or the end of the selection.
  </dd>
  <dt id="charCoords"><code>charCoords(pos) → object</code></dt>
  <dd>Like <code>cursorCoords</code>, but returns the position of
    an arbitrary characters. <code>pos</code> should be
    a <code>{line, ch}</code> object.
  </dd>
  <dt id="coordsChar"><code>coordsChar(object) → pos</code></dt>
  <dd>Given an <code>{x, y}</code> object (in page coordinates),
    returns the <code>{line, ch}</code> position that corresponds to
    it.
  </dd>

  <dt id="undo"><code>undo()</code></dt>
  <dd>Undo one edit (if any undo events are stored).</dd>
  <dt id="redo"><code>redo()</code></dt>
  <dd>Redo one undone edit.</dd>
  <dt id="historySize"><code>historySize() → object</code></dt>
  <dd>Returns an object with <code>{undo, redo}</code> properties,
    both of which hold integers, indicating the amount of stored
    undo and redo operations.
  </dd>
  <dt id="clearHistory"><code>clearHistory()</code></dt>
  <dd>Clears the editor's undo history.</dd>

  <dt id="indentLine"><code>indentLine(line, dir)</code></dt>
  <dd>Reset the given line's indentation to the indentation
    prescribed by the mode. If the second argument is given,
    indentation will be increased (if <code>dir</code> is true) or
    decreased (if false) by an <a href="#option_indentUnit">indent
      unit</a> instead.
  </dd>

  <dt id="getSearchCursor"><code>getSearchCursor(query, start, caseFold) → cursor</code></dt>
  <dd>Used to implement search/replace
    functionality. <code>query</code> can be a regular expression or
    a string (only strings will match across lines—if they contain
    newlines). <code>start</code> provides the starting position of
    the search. It can be a <code>{line, ch}</code> object, or can
    be left off to default to the start of the
    document. <code>caseFold</code> is only relevant when matching a
    string. It will cause the search to be case-insensitive. A
    search cursor has the following methods:
    <dl>
      <dt><code>findNext(), findPrevious() → boolean</code></dt>
      <dd>Search forward or backward from the current position.
        The return value indicates whether a match was found. If
        matching a regular expression, the return value will be the
        array returned by the <code>match</code> method, in case you
        want to extract matched groups.
      </dd>
      <dt><code>from(), to() → object</code></dt>
      <dd>These are only valid when the last call
        to <code>findNext</code> or <code>findPrevious</code> did
        not return false. They will return <code>{line, ch}</code>
        objects pointing at the start and end of the match.
      </dd>
      <dt><code>replace(text)</code></dt>
      <dd>Replaces the currently found match with the given text
        and adjusts the cursor position to reflect the
        replacement.
      </dd>
    </dl>
  </dd>

  <dt id="getTokenAt"><code>getTokenAt(pos) → object</code></dt>
  <dd>Retrieves information about the token the current mode found
    at the given position (a <code>{line, ch}</code> object). The
    returned object has the following properties:
    <dl>
      <dt><code>start</code></dt>
      <dd>The character (on the given line) at which the token starts.</dd>
      <dt><code>end</code></dt>
      <dd>The character at which the token ends.</dd>
      <dt><code>string</code></dt>
      <dd>The token's string.</dd>
      <dt><code>className</code></dt>
      <dd>The class the mode assigned
        to the token. (Can be null when no class was assigned.)
      </dd>
      <dt><code>state</code></dt>
      <dd>The mode's state at the end of this token.</dd>
    </dl>
  </dd>

  <dt id="markText"><code>markText(from, to, className) → function</code></dt>
  <dd>Can be used to mark a range of text with a specific CSS
    class name. <code>from</code> and <code>to</code> should
    be <code>{line, ch}</code> objects. The method will return an
    object with two methods, <code>clear()</code>, which removes the
    mark, and <code>find()</code>, which returns a <code>{from,
      to}</code> (both document positions), indicating the current
    position of the marked range.
  </dd>

  <dt id="setMarker"><code>setMarker(line, text, className) → lineHandle</code></dt>
  <dd>Add a gutter marker for the given line. Gutter markers are
    shown in the line-number area (instead of the number for this
    line). Both <code>text</code> and <code>className</code> are
    optional. Setting <code>text</code> to a Unicode character like
    ● tends to give a nice effect. To put a picture in the gutter,
    set <code>text</code> to a space and <code>className</code> to
    something that sets a background image. If you
    specify <code>text</code>, the given text (which may contain
    HTML) will, by default, replace the line number for that line.
    If this is not what you want, you can include the
    string <code>%N%</code> in the text, which will be replaced by
    the line number.
  </dd>
  <dt id="clearMarker"><code>clearMarker(line)</code></dt>
  <dd>Clears a marker created
    with <code>setMarker</code>. <code>line</code> can be either a
    number or a handle returned by <code>setMarker</code> (since a
    number may now refer to a different line if something was added
    or deleted).
  </dd>
  <dt id="setLineClass"><code>setLineClass(line, className) → lineHandle</code></dt>
  <dd>Set a CSS class name for the given line. <code>line</code>
    can be a number or a line handle (as returned
    by <code>setMarker</code> or this function).
    Pass <code>null</code> to clear the class for a line.
  </dd>

  <dt id="lineInfo"><code>lineInfo(line) → object</code></dt>
  <dd>Returns the line number, text content, and marker status of
    the given line, which can be either a number or a handle
    returned by <code>setMarker</code>. The returned object has the
    structure <code>{line, text, markerText, markerClass}</code>.
  </dd>

  <dt id="addWidget"><code>addWidget(pos, node, scrollIntoView)</code></dt>
  <dd>Puts <code>node</code>, which should be an absolutely
    positioned DOM node, into the editor, positioned right below the
    given <code>{line, ch}</code> position.
    When <code>scrollIntoView</code> is true, the editor will ensure
    that the entire node is visible (if possible). To remove the
    widget again, simply use DOM methods (move it somewhere else, or
    call <code>removeChild</code> on its parent).
  </dd>

  <dt id="matchBrackets"><code>matchBrackets()</code></dt>
  <dd>Force matching-bracket-highlighting to happen.</dd>

  <dt id="lineCount"><code>lineCount() → number</code></dt>
  <dd>Get the number of lines in the editor.</dd>

  <dt id="getCursor"><code>getCursor(start) → object</code></dt>
  <dd><code>start</code> is a boolean indicating whether the start
    or the end of the selection must be retrieved. If it is not
    given, the current cursor pos, i.e. the side of the selection
    that would move if you pressed an arrow key, is chosen.
    A <code>{line, ch}</code> object will be returned.
  </dd>
  <dt id="somethingSelected"><code>somethingSelected() → boolean</code></dt>
  <dd>Return true if any text is selected.</dd>
  <dt id="setCursor"><code>setCursor(pos)</code></dt>
  <dd>Set the cursor position. You can either pass a
    single <code>{line, ch}</code> object, or the line and the
    character as two separate parameters.
  </dd>
  <dt id="setSelection"><code>setSelection(start, end)</code></dt>
  <dd>Set the selection range. <code>start</code>
    and <code>end</code> should be <code>{line, ch}</code> objects.
  </dd>

  <dt id="getLine"><code>getLine(n) → string</code></dt>
  <dd>Get the content of line <code>n</code>.</dd>
  <dt id="setLine"><code>setLine(n, text)</code></dt>
  <dd>Set the content of line <code>n</code>.</dd>
  <dt id="removeLine"><code>removeLine(n)</code></dt>
  <dd>Remove the given line from the document.</dd>

  <dt id="getRange"><code>getRange(from, to) → string</code></td>
  <dd>Get the text between the given points in the editor, which
    should be <code>{line, ch}</code> objects.
  </dd>
  <dt id="replaceRange"><code>replaceRange(string, from, to)</code></dt>
  <dd>Replace the part of the document between <code>from</code>
    and <code>to</code> with the given string. <code>from</code>
    and <code>to</code> must be <code>{line, ch}</code>
    objects. <code>to</code> can be left off to simply insert the
    string at position <code>from</code>.
  </dd>

  <dt id="coordsFromIndex"><code>coordsFromIndex(index) → object</code></dt>
  <dd>Calculates and returns a <code>{line, ch}</code> object for a
    zero-based <code>index</code> who's value is relative to the start of the
    editor's text. If the <code>index</code> is out of range of the text then
    the returned object is clipped to start or end of the text
    respectively.
  </dd>
</dl>

<p>The following are more low-level methods:</p>

<dl>
  <dt id="operation"><code>operation(func) → result</code></dt>
  <dd>CodeMirror internally buffers changes and only updates its
    DOM structure after it has finished performing some operation.
    If you need to perform a lot of operations on a CodeMirror
    instance, you can call this method with a function argument. It
    will call the function, buffering up all changes, and only doing
    the expensive update after the function returns. This can be a
    lot faster. The return value from this method will be the return
    value of your function.
  </dd>

  <dt id="refresh"><code>refresh()</code></dt>
  <dd>If your code does something to change the size of the editor
    element (window resizes are already listened for), or unhides
    it, you should probably follow up by calling this method to
    ensure CodeMirror is still looking as intended.
  </dd>

  <dt id="getInputField"><code>getInputField() → textarea</code></dt>
  <dd>Returns the hiden textarea used to read input.</dd>
  <dt id="getWrapperElement"><code>getWrapperElement() → node</code></dt>
  <dd>Returns the DOM node that represents the editor. Remove this
    from your tree to delete an editor instance.
  </dd>
  <dt id="getScrollerElement"><code>getScrollerElement() → node</code></dt>
  <dd>Returns the DOM node that is responsible for the sizing and
    the scrolling of the editor. You can change
    the <code>height</code> and <code>width</code> styles of this
    element to resize an editor. (You might have to call
    the <a href="#refresh"><code>refresh</code></a> method
    afterwards.)
  </dd>
  <dt id="getGutterElement"><code>getGutterElement() → node</code></dt>
  <dd>Fetches the DOM node that represents the editor gutter.</dd>

  <dt id="getStateAfter"><code>getStateAfter(line) → state</code></dt>
  <dd>Returns the mode's parser state, if any, at the end of the
    given line number. If no line number is given, the state at the
    end of the document is returned. This can be useful for storing
    parsing errors in the state, or getting other kinds of
    contextual information for a line.
  </dd>
</dl>

<p id="fromTextArea">Finally, the <code>CodeMirror</code> object
  itself has a method <code>fromTextArea</code>. This takes a
  textarea DOM node as first argument and an optional configuration
  object as second. It will replace the textarea with a CodeMirror
  instance, and wire up the form of that textarea (if any) to make
  sure the editor contents are put into the textarea when the form
  is submitted. A CodeMirror instance created this way has two
  additional methods:</p>

<dl>
  <dt id="save"><code>save()</code></dt>
  <dd>Copy the content of the editor into the textarea.</dd>

  <dt id="toTextArea"><code>toTextArea()</code></dt>
  <dd>Remove the editor, and restore the original textarea (with
    the editor's current content).
  </dd>
</dl>

<p id="defineExtension">If you want to define extra methods in terms
  of the CodeMirror API, it is possible to
  use <code>CodeMirror.defineExtension(name, value)</code>. This
  will cause the given value (usually a method) to be added to all
  CodeMirror instances created from then on.</p>

<h2 id="modeapi">Writing CodeMirror Modes</h2>

<p>Modes typically consist of a JavaScript file and a CSS file.
  The CSS file (see, for
  example <a href="mode/javascript/javascript.css"><code>javascript.css</code></a>)
  defines the classes that will be used to style the syntactic
  elements of the code, and the script contains the logic to
  actually assign these classes to the right pieces of text.</p>

<p>You'll usually want to use some kind of prefix for your CSS
  classes, so that they are unlikely to clash with other classes,
  both those used by other modes and those defined by the page in
  which CodeMirror is embedded.</p>

<p id="defineMode">The mode script should
  call <code>CodeMirror.defineMode</code> to register itself with
  CodeMirror. This function takes two arguments. The first should be
  the name of the mode, for which you should use a lowercase string,
  preferably one that is also the name of the files that define the
  mode (i.e. <code>"xml"</code> is defined <code>xml.js</code>). The
  second argument should be a function that, given a CodeMirror
  configuration object (the thing passed to
  the <code>CodeMirror</code> function) and a mode configuration
  object (as in the <a href="#option_mode"><code>mode</code></a>
  option), returns a mode object.</p>

<p>Typically, you should use this second argument
  to <code>defineMode</code> as your module scope function (modes
  should not leak anything into the global scope!), i.e. write your
  whole mode inside this function.</p>

<p>The main responsibility of a mode script is <em>parsing</em>
  the content of the editor. Depending on the language and the
  amount of functionality desired, this can be done in really easy
  or extremely complicated ways. Some parsers can be stateless,
  meaning that they look at one element (<em>token</em>) of the code
  at a time, with no memory of what came before. Most, however, will
  need to remember something. This is done by using a <em>state
    object</em>, which is an object that can be mutated every time a
  new token is read.</p>

<p id="startState">Modes that use a state must define
  a <code>startState</code> method on their mode object. This is a
  function of no arguments that produces a state object to be used
  at the start of a document.</p>

<p id="token">The most important part of a mode object is
  its <code>token(stream, state)</code> method. All modes must
  define this method. It should read one token from the stream it is
  given as an argument, optionally update its state, and return a
  style string, or <code>null</code> for tokens that do not have to
  be styled. For your styles, you can either use the 'standard' ones
  defined in the themes (without the <code>cm-</code> prefix), or
  define your own (as the <a href="../mode/diff/index.html">diff</a>
  mode does) and have people include a custom theme for your
  mode.

<p>

<p id="StringStream">The stream object encapsulates a line of code
  (tokens may never span lines) and our current position in that
  line. It has the following API:</p>

<dl>
  <dt><code>eol() → boolean</code></dt>
  <dd>Returns true only if the stream is at the end of the
    line.
  </dd>
  <dt><code>sol() → boolean</code></dt>
  <dd>Returns true only if the stream is at the start of the
    line.
  </dd>

  <dt><code>peek() → character</code></dt>
  <dd>Returns the next character in the stream without advancing
    it. Will return <code>undefined</code> at the end of the
    line.
  </dd>
  <dt><code>next() → character</code></dt>
  <dd>Returns the next character in the stream and advances it.
    Also returns <code>undefined</code> when no more characters are
    available.
  </dd>

  <dt><code>eat(match) → character</code></dt>
  <dd><code>match</code> can be a character, a regular expression,
    or a function that takes a character and returns a boolean. If
    the next character in the stream 'matches' the given argument,
    it is consumed and returned. Otherwise, <code>undefined</code>
    is returned.
  </dd>
  <dt><code>eatWhile(match) → boolean</code></dt>
  <dd>Repeatedly calls <code>eat</code> with the given argument,
    until it fails. Returns true if any characters were eaten.
  </dd>
  <dt><code>eatSpace() → boolean</code></dt>
  <dd>Shortcut for <code>eatWhile</code> when matching
    white-space.
  </dd>
  <dt><code>skipToEnd()</code></dt>
  <dd>Moves the position to the end of the line.</dd>
  <dt><code>skipTo(ch) → boolean</code></dt>
  <dd>Skips to the next occurrence of the given character, if
    found on the current line (doesn't advance the stream if the
    character does not occur on the line). Returns true if the
    character was found.
  </dd>
  <dt><code>match(pattern, consume, caseFold) → boolean</code></dt>
  <dd>Act like a
    multi-character <code>eat</code>—if <code>consume</code> is true
    or not given—or a look-ahead that doesn't update the stream
    position—if it is false. <code>pattern</code> can be either a
    string or a regular expression starting with <code>^</code>.
    When it is a string, <code>caseFold</code> can be set to true to
    make the match case-insensitive. When successfully matching a
    regular expression, the returned value will be the array
    returned by <code>match</code>, in case you need to extract
    matched groups.
  </dd>

  <dt><code>backUp(n)</code></dt>
  <dd>Backs up the stream <code>n</code> characters. Backing it up
    further than the start of the current token will cause things to
    break, so be careful.
  </dd>
  <dt><code>column() → integer</code></dt>
  <dd>Returns the column (taking into account tabs) at which the
    current token starts. Can be used to find out whether a token
    starts a new line.
  </dd>
  <dt><code>indentation() → integer</code></dt>
  <dd>Tells you how far the current line has been indented, in
    spaces. Corrects for tab characters.
  </dd>

  <dt><code>current() → string</code></dt>
  <dd>Get the string between the start of the current token and
    the current stream position.
  </dd>
</dl>

<p id="blankLine">By default, blank lines are simply skipped when
  tokenizing a document. For languages that have significant blank
  lines, you can define a <code>blankLine(state)</code> method on
  your mode that will get called whenever a blank line is passed
  over, so that it can update the parser state.</p>

<p id="copyState">Because state object are mutated, and CodeMirror
  needs to keep valid versions of a state around so that it can
  restart a parse at any line, copies must be made of state objects.
  The default algorithm used is that a new state object is created,
  which gets all the properties of the old object. Any properties
  which hold arrays get a copy of these arrays (since arrays tend to
  be used as mutable stacks). When this is not correct, for example
  because a mode mutates non-array properties of its state object, a
  mode object should define a <code>copyState</code> method,
  which is given a state and should return a safe copy of that
  state.</p>

<p id="compareStates">By default, CodeMirror will stop re-parsing
  a document as soon as it encounters a few lines that were
  highlighted the same in the old parse as in the new one. It is
  possible to provide an explicit way to test whether a state is
  equivalent to another one, which CodeMirror will use (instead of
  the unchanged-lines heuristic) to decide when to stop
  highlighting. You do this by providing
  a <code>compareStates</code> method on your mode object, which
  takes two state arguments and returns a boolean indicating whether
  they are equivalent. See the XML mode, which uses this to provide
  reliable highlighting of bad closing tags, as an example.</p>

<p id="indent">If you want your mode to provide smart indentation
  (see <a href="#option_enterMode"><code>entermode</code></a>
  and <a href="#option_tabMode"><code>tabMode</code></a> when they
  have a value of <code>"indent"</code>), you must define
  an <code>indent(state, textAfter)</code> method on your mode
  object.</p>

<p>The indentation method should inspect the given state object,
  and optionally the <code>textAfter</code> string, which contains
  the text on the line that is being indented, and return an
  integer, the amount of spaces to indent. It should usually take
  the <a href="#option_indentUnit"><code>indentUnit</code></a>
  option into account.</p>

<p id="electricChars">Finally, a mode may define
  an <code>electricChars</code> property, which should hold a string
  containing all the characters that should trigger the behaviour
  described for
  the <a href="#option_electricChars"><code>electricChars</code></a>
  option.</p>

<p>So, to summarize, a mode <em>must</em> provide
  a <code>token</code> method, and it <em>may</em>
  provide <code>startState</code>, <code>copyState</code>,
  and <code>indent</code> methods. For an example of a trivial mode,
  see the <a href="mode/diff/diff.js">diff mode</a>, for a more
  involved example, see
  the <a href="mode/javascript/javascript.js">JavaScript
    mode</a>.</p>

<p>Sometimes, it is useful for modes to <em>nest</em>—to have one
  mode delegate work to another mode. An example of this kind of
  mode is the <a href="mode/htmlmixed/htmlmixed.js">mixed-mode HTML
    mode</a>. To implement such nesting, it is usually necessary to
  create mode objects and copy states yourself. To create a mode
  object, there are <code>CodeMirror.getMode(options,
    parserConfig)</code>, where the first argument is a configuration
  object as passed to the mode constructor function, and the second
  argument is a mode specification as in
  the <a href="#option_mode"><code>mode</code></a> option. To copy a
  state object, call <code>CodeMirror.copyState(mode, state)</code>,
  where <code>mode</code> is the mode that created the given
  state.</p>

<p>To make indentation work properly in a nested parser, it is
  advisable to give the <code>startState</code> method of modes that
  are intended to be nested an optional argument that provides the
  base indentation for the block of code. The JavaScript and CSS
  parser do this, for example, to allow JavaScript and CSS code
  inside the mixed-mode HTML mode to be properly indented.</p>

<p>Finally, it is possible to associate your mode, or a certain
  configuration of your mode, with
  a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type. For
  example, the JavaScript mode associates itself
  with <code>text/javascript</code>, and its JSON variant
  with <code>application/json</code>. To do this,
  call <code>CodeMirror.defineMIME(mime, modeSpec)</code>,
  where <code>modeSpec</code> can be a string or object specifying a
  mode, as in the <a href="#option_mode"><code>mode</code></a>
  option.</p>

</div>
<div class="rightsmall blk">

  <h2>Contents</h2>

  <ul>
    <li><a href="#overview">Overview</a></li>
    <li><a href="#usage">Basic Usage</a></li>
    <li><a href="#config">Configuration</a></li>
    <li><a href="#styling">Customized Styling</a></li>
    <li><a href="#api">Programming API</a></li>
    <li><a href="#modeapi">Writing CodeMirror Modes</a></li>
  </ul>

</div>
</div>

<div style="height: 2em">&nbsp;</div>

</body>
</html>
